An Italian court convicted seven scientists and experts of manslaughter on Monday for failing to adequately warn citizens before an earthquake struck L'Aquila in central Italy in 2009, killing more than 300 people.

The court in L'Aquila sentenced the defendants to six years in prison. Each is a member of the country's Grand Commission on High Risks.

In Italy, convictions aren't definitive until after at least one level of appeals, so it is unlikely any of the defendants will face jail immediately.

Scientists worldwide had decried the trial as ridiculous, contending that science has no reliable way to predict earthquakes.

Among those convicted were some of Italy's most prominent and internationally respected seismologists and geological experts, including Enzo Boschi, former head of the country's Institute of Geophysics and Volcanology.

"I am dejected, desperate," Boschi said after the verdict. "I thought I would have been acquitted. I still don't understand what I was convicted of."

The trial began in September 2011 in L'Aquila, whose devastated historic centre is still largely a ghost town.

The defendants were accused of giving "inexact, incomplete and contradictory information" about whether small tremors felt by L'Aquila residents in the weeks and months before the 6 April 2009 quake should have constituted grounds for a quake warning.

The 6.3-magnitude quake killed 308 people in and around the medieval town and forced survivors to live in tent camps for months.

Many much smaller tremors had rattled the area in the months before the quake, causing frightened people to wonder if they should evacuate.

"I consider myself innocent before God and men," said another convicted defendant, Bernardo De Bernardinis, a former official of Italy's Civil Protection Agency.

Prosecutors had sought a conviction and four-year sentences during the non-jury trial, which was led by a judge.

A defence lawyer, Filippo Dinacci, told reporters that the sentence would have "big repercussions" on public administration since officials would be afraid to "do anything."

Roger Musson, head of seismic hazards and archives at the British Geological Survey, said: "This is a very sad business indeed, these are people I know, who were doing their best to give an accurate account of large earthquakes. It seems to be wrong that they should be prosecuted for offering scientific advice to the best of their ability."

He added: "It will certainly make scientists less free in speaking out where perhaps their expertise is really needed."

John Elliott of Oxford University's Department of Earth Sciences said: "This verdict is a sad end to a tragic series of events in L'Aquila. Earthquakes cannot be predicted, and these scientists should not even have been on trial accused of providing incomplete information, because it is unfair to have expected them to have provided an exact and complete warning of an earthquake in the first place – this is something which is not yet credibly possible for earthquake science."